Power back gauge



Aug. 27, 1940.

w. c. EICKMAN 2,213,068

POWER BACK GAUGE Filed March '7, 1939 5 Sheets-Sheet l INVENTOR. W44 meC. [7CK/7 9N A TTORNEYS W. C. EICKMAN POWER BACK GAUGE Aug. 27, 1940.

Filed March '7, 1939 3 Sheets-Sheet 5 IN VENTOR.

14 41. 752 C. flex/W417 j W y/ a mf ATTORNEK-S Patented Aug. 27, 1940UNITED STATES 2,2l3,ll68

ATENT orrics PQWER BACK GAUGE Walter C. Eicknian, Dayton, Ohio, assignorto i-larris- Seybold-lotter Company, Cleveland,

8 Claims.

This invention relates to improvements in power back gauges, that is tosay apparatus for controlling the application of power to cause the backgauge of a paper cutter to travel in the forward or rearward direction.In accordance with the present invention the driving motor is stoppedquickly by reversing the direction of current flow, so that dynamicbraking is utilized, sometimes called plugging the motor, this featureof the invention having the highly important result that no drag isimposed upon the apparatus and the latter is free to be actuated bymeans of the usual hand wheel. In other words, the operator by pressingthe proper switch button can cause the electric motor to advance theback gauge to a position just short of the desired point of cut,stopping the motor and consequently the drive mechanism quickly andpositively, after which he may operate the hand wheel to eifect thefinal fine adjustment of the pile up to the cutting line.

I am aware that paper cutters have been equipped with motor drives andbraking means therefor to effect a quick stop and prevent coasting, asfor example in Lehman Patent 2,133,031, but the automatic application ofbrakes when the current to the motor is turned ofi means that thebraking eifort is present to oppose the actuation of the back gauge byhand for completing the necessary travel up to the point of cut. Inorder to be effective for quickly stopping the back gauge such brakingeffort must be substantial, and consequently it becomes quite difiicultto operate the hand wheel.

One of the principal objects of the invention therefore is to providebraking for the driving motor without interposing resistance to handoperation of the back gauge.

Another object of the invention is the provision of a novel controlsystem for the forward and reverse circuits to the motor.

A further object is the provision of means for automatically stoppingthe rearward travel of the back gauge at different selected pointsforward of the rearmost position, so that considerable time is saved inhandling stacks of relatively short sheets.

Other objects and features of novelty will appear as I proceed with thedescription of that embodiment of the invention which, for the purposesof the present application, I have illustrated in the accompanyingdrawings, in which Fig. 1 is a plan view of a paper cutter with theclamp and knife and most of the superstructure removed for the sake ofclearness.

Fig. 2 is a side elevational view of the same.

(Cl. l64--59) Fig. 3 is a detailed elevational view of a zero speedswitch which may be employed in connection with the invention.

Fig. 4 is a wiring diagram showing the control means for the drivingmotor.

In the drawings I have shown at ill and H supports or legs upon whichthe table 12 is carried. The cutting stick it is mounted in a groove inthe table in the conventional manner, the knife being indicated at it inFig. 2. I5 is a back gauge of conventional form which is slidablysupported upon the table for movement backward and forward and isprovided with a depending plate it which projects downwardly through alongitudinal slot il in the table and carries an elongated nut 58 thatencircles and engages a drive screw 59 also of conventional formjournaled underneath the table. At its front end the screw i9 has pinnedor otherwise secured thereto a wheel As will be obvious the gauge i5 maybe fed forward or backward by operation of the hand wheel.

Horizontal pulleys 2i and 22 are mounted on fixed elements of themachine near the front and rear ends thereof. An endless steel tape 23runs upon the pulleys 2i and 22, being operatively connected with thegauge by means of a post 24 which is mounted in the gauge and isattached to the tape. The latter has a length scale engraved thereuponand is employed in the usual manner to indicate the position of thegauge, this being particularly advantageous upon a machine equipped witha driving motor because of the relatively rapid movement of the gauge insuch machines.

The power drive for feed screw it is taken from an electric motor 25carried upon the under side of the table and connected with the screw bymeans of pulleys 2E and El pinned to the motor shaft and feed screwrespectively and a flexible belt 28. The motor is reversible and isaccordingly capable of turning the screw in either direction so as tooperate the gauge either forwardly or backwardly. Hand controls for themotor are contained in a switch box 2&3 at the front end of the machineconvenient to the operator and comprise push button switches T, f and s.The I switch inaugurates and maintains forward movement of the backgauge so long as the switch button is depressed. Forward movement isusually by steps corresponding to the work travel that is necessary tobring the pile into position for the different lines of cut. The 1switch inaugurates rearward travel, but directly after it has beendepressed the operator may.

remove his finger from the 1" switch and the rearward travel willcontinue until interrupted automatically as hereinafter explained oruntilthe operator presses the 3 button which stops rear- 5 Ward travelimmediately.

From the switch box 29 a conduit 30 extends rearwardl y to a relay panel3i supported upon the under side of the table. From the panel 29 anotherconduit 32 leads to the motor. From the 10 main conduit 30 a branchconduit 33 leads to a front limit switch LSF provided with an arm 3tthat is adapted to be engaged and actuated by an arm 35 mounted on theback gauge. A, second limit switch LSP may be termed a portable limit l5switch since it is adjustable upon a fixed part of the machine,preferably upon one of the side gauges 36. A clamping screw 3'! isprovided for holding the switch in any selected position. This switchhas an operating arm 38 that is adapted 20 to be engaged by anupstanding plate 39 on the back gauge during the rearward movement ofthe :latter. A flexible cable 40 carries the conductors for switch LSPfrom the main conduit at to the switch; A third limit switch LSRprovided with 25v an operating arm M is mounted beneath the table at therear of the machine. The arm 4! is 1 adapted to be-engaged by 2.depending extension 42 on the nut E8 to stop rearward travel in the Ievent that the limit switch LSP is not in use.

.30 'Ifhe switch LSR. is connected with the conduit 32 by a branchconduit 43.

Motor 25 has a double-ended shaft. The switch ZS known as a zero speedswitch is opera- I tively connected with one end of the shaft. This 35switch is illustrated somewhat in detail in Fig. 3

f the drawings. In that figure the motor shaft is shown at i l. It isprovided with a pulley 55 over which extends a flexible belt 46 that isattached at its ends to a rock arm ll pivotally con- 41) nected with asupport at 18. When the motor shaft rotates clockwise or anti-clockwisethe arm 4'! tilts to the right or to the left, as the case may be, andelectric contact buttons 39 or en- ';gage fixedcontact buttons 5! or 52respectively. 45 A flexible conductor 53 connects rock arm ll with abinding post 54, and a spring detent 55 tends .to holdthe arm 47 in thecentral position illustrated. Contacts 51 and 52 are electricallyconnected with binding posts 53 and 57 respectively.

60.fI 'he friction between pulley 55 and belt it is relatively light anddoes not cause rapid wear, and if the belt should break the springdetent will return the switch to the middle or off position.

Referring now to Fig. 4, L1, L2 and L3 represent line'wires from whichconductors til, 55 and 62 lead to terminals of a magnetic contactor 153,further conductors 60', 6! and 52' leading to ;terminals of anothermagnetic contactor Ed.

,BO-Each of these contactors has three cross arms,

7 those of contactor 63 being numbered 65, t5 and 61, while thoseofcontactor t -l are numbered -65, 66' and 61, respectively.

It will be noted that the conductors 6t and lit fli both lead to theupper cross arms of the two contactors. The conductors 5i and 52 howeverleadto the middle and lower arms 65 and El re- :spectively of 'contactor63, while conductors t! :and 62 have the reverse arrangement, that is-70"to say they lead respectively to the lower and middle arms 6'! and66 of contactor i5 5. Correspo'nding terminals of the two contactors areconnected by conductors 68, 69 and it, and from Zthese conductors'leads1! l2 and 73 extend to :qythe motor. M. a

' electrically join contacts 77 and'iil l.

Switch box 29 is connected with line wire L1 via conductors l4 and 15which lead to lower contacts l5 and Ti for the reverse and forward pushbutton switches r and f respectively, the connection between contacts 76and ll being by way of a short conductor it. Another short conductor itconnects an upper contact 88 for switch 1 with an upper contact 8i ofthe stop push button switch s. The other contact 82 of the latter switchis connected by a conductor 83 with the contact 52 of the ZS switch anda short conductor 36 joins conductor 83 with the remaining contact 85 ofthe push button switch 1.

R, and F are relay coils which when energized one at a time serve toraise the magnetic contactors t3 and Ed and cause the cross arms thereofto engage the corresponding terminals. The coil R also operates a relayarmature 85 with cross arms 8? and 88. Coil F operates a relay armature8% with the cross arm 96.

RR and FF are auxiliary relay coils, the armatures of which each have asingle cross arm 9! and 92 respectively. From line wire L3 there extendsa conductor 93 within which is interposed limit switch LSF and aconductor 9 3 which leads to the two coils F and FF. From the oppositeend of coil F conductors 95, Q8 and 9? lead to a contact 98 normallyengaged by cross arm and from coil FF conductors 99, itt and Hill leadto the other contact M2 for armature cross arm 38, while from thiscontact a conductor we leads to point it i of push button switch 1.

The lower ends of coils R and RR, are connected together and a conductori635 extends therefrom to line wire L3 through limit switches LS]? andLSR. The upper end of coil RE. is connected by a short conductor m6 withconductor t3 and by other conductors Sill, Hi8 and 5&9 with a contact MBof relay 89, 9%. The other contact ill is connected by conductors H2, H3and E; it with the upper end of coil R.

The remaining upper contact N5 of push button switch 1 is connected by aconductor I 56 with a contact Ml located above the normal position ofcross arm 87 on relay 86. The other contact M6 for the same arm isjoined by a conductor M3 with conductor 99. A short conductor I23extends from conductor 5 to a contact Hi located above the normalposition of relay arm 9!,'

and the other contact E22 of this relay is joined by a conductor '523to. a contact for relay t2, the other contact E25 being connecteddirectly with conductor l4. From conductor 123 a conductor i235extendsupwardly to and is electrically joined with flexible conductor 53of the ZS switch;

' The operation of the system embodies the following procedure: in orderto move the back gauge forward from'an idle position in which thecontrol apparatus is in the condition illustrated in Fig. 4-, theoperator pushes in button to Relay coil F is thereby energized throughthe following circuit: from line wire L1 through conductors '55, i5 andit, across contacts ii and iii i, then through conductor itt, cross arm88 and conductors ill, 9% and 95 to coil F and back through conductors9A1 and $33 to line wire L3. Simultaneously coil FF is energized becauseof current passing as before through the contacts of switch button I andconductor M33 through conductors- Edi, tilt and 98 to coil FF and backto line wire- L1, L2 and L3 to the motor lvi to drive thelattera in thedirection to cause forward travel of the back gauge.

The rotation of the motor in a forward direction swings the rock arm 47of the zero speed switch ZS in the anti-clockwise direction, bringingthe contacts 50 and 52 into engagement. A circuit is then set up fromline wire L1 through conductor It, across cross arm 92, then in theraised position, through conductors I26 and 53 to the switch ZS and byway of contacts 50 and 52 and conductors 83 and I05 to coil RR and backthrough conductor I05, and limit switches LSP and LSR to line wire L3.This raises cross arm SI and seals in coil RR by way of conductors "I4and I29, relay 9|, conductors I23, I26 and 53, switch ZS, conductors 83and I06 to the coil, and back through conductor I05 and limit switchesLS? and LSR to line wire L3. The motor continues to run the back gaugeforward so long as the operator continues to depress push button 1, butwhen he lifts his finger the circuit through coil F is broken andmagnetic contactor 64 falls. At the same time relay cross arm 90 fallsto make connection across the contacts H and III whereupon a circuit isset up through reverse relay coil R as follows: through conductors I4and I29, cross arm 9I, conductors I23, I26 and 53, switch ZS, conductors83, I06, I01, I08 and I09, cross arm 50 and conductors IIZ, IIE and H4to coil R, and back through conductor I and limit switches LSP and LSRto the line L3. Magnetic contactor 63 is thereby raised and current fromthe line is supplied to the motor M, tending to cause rotation in theopposite direction, or clockwise as viewed in Fig. 4-. The motortherefore comes to a quick stop and begins to reverse, but the firstmovement in that direction causes the rock arm II to swing clockwise,opening the circuit through coil R at the contacts 50, 52. All parts ofthe system are therefore returned to the condition illustrated in thedrawings.

If the operator should hold the button 1 de pressed until the back gaugetoo nearly approaches the knife of the machine, switch LSF would beopened, cutting out coil F but not coil Current reversal would thereforeoccur as before and the back gauge would come to aquick stop.

When the back gauge is at the forward end of its travel and the operatordesires to return it in order that a new pile of sheets may be arrangedon the table, the operator momentarily depresses push button 1. Circuitsare then set up through coils R and RR, first from line wire L1 throughconductors '14 and I5, switch 1", conductors 84, 83, I06, I52, I08 andI09, cross arm 90, conductors H2, H3 and H4 to coil R and back throughconductor I05, and limit switches LSP and LSR to line ,wire L3, alsofrom conductor 83 through conductor I06 to coil RR and back throughconductor I05 and limit switches LSP and LSR to the line. This raisesmagnetic contactorfit and sets up current flow in the motor causing itto turn in a clockwise direction as viewed in Fig. 4, and bringing ZSswitch contacts 29 and iii into engagement.

The raising of the cross arm 9I sets up a circuit through FF by way ofconductors 14 and I20, cross arm 98, conductors I23, I26, and 53,contacts 49 and SI of switch ZS, thence to coil FF and back throughconductors 94 and 93 to line wire L3. The coil FF seals itself viaconductor l4, cross arm 92, conductors I23, I26 and 53 and switch ZS tocoil FF, and back through conductors 94 and 93 to the line. Auxiliarycircuits through coils R and RR are then set up, first from line wire L1through conductors I4 and I20, cros arm 9|, conductors I23, I26 and 53,switch ZS, conductors 99 and I I9, cross arm 87 and conductor H6, acrossthe upper contacts of push button switch f, through conductor I9 andpush button switch s, through conductors 83, I06 to coil RR and alsothrough conductors Nil, I08 and I09, across cross arm 95, and throughconductors H2, H3 and lid to coil R and back through conductor I65, andlimit switches LSP and LSR to line wire L3. Hence after momentarydepression of reverse push button r the latter may be released and therearward movement of the back gauge will continue through the auxiliarycircuit until the latter circuit is opened on account of the opening ofone or" the limit switches LSP or LSR. When this occurs coils R and RRare deenergized, but the coil FF continues to be energized. A circuit isthen set up through coil F via conductor I l, cross arm 92, conductorsI23, I25 and 53, switch ZS, conductors 99, I0!) and NH, cross arm 83,conductors SI, 96 and 95 to coil F, and back through conductors 84 and93 to the line. Magnetic contactor 64 is thereby raised and currentflows through the motor M in a direction to oppose its motion at thetime, thereby bringing it to a quick stop, whereupon the circuit isbroken at the switch ZS.

In case the operator desires to interrupt the reverse movement of theback gauge before it is stopped by a limit switch, he depresses push button s which breaks the auxiliary or parallel circuit previouslydescribed, so that a stop is effected in the same manner as before.

It is also possible for the operator to stop rearward motion of the backgauge and inaugurate forward motion immediately by depressing theforward push button 1, which by reason of breaking the auxiliary orparallel circuit at the push button results in plugging the motor to astop and instantly starting it forward.

In practice the forward and reverse magnetic contactors 6 1 and 63 aremechanically interlocked to prevent any possibility of short-circuitingacross the line.

Having thus described my invention, I claim:

1. In a paper cutter, the combination of a table, a back gauge movablethereover, a drive for said back gauge, a hand wheel for operating saiddrive, an electric motor also operatively connected with said drive,means for conducting current to said motor, and means for reversing thecurrent connections to the motor to effect a quick stop, whereby thehand wheel may be turned thereafter Without drag other than the loadimposed by the resistance to movement of the back gauge itself.

2. In a paper cutter, the combination of a table, a back gauge movablethereover, a screw feed for said back gauge operable in eitherdirection, an endless tape scale operatively connected with said gaugeand movable lengthwise of the table for indicating the position of thegauge, a hand wheel for operating said screw feed, an electric motoralso operatively connected with said screw feed, means for conductingcurrent to said motor, and means for reversing the current connectionsto the motor to eifect a quick stop, whereby the hand wheel may beturned thereafter without drag other than the load imposed by theresistance to movement of the back gauge itself.

3. In a paper cutter, a table, a side gauge affixed to the table, a backgauge slidable over the surface of the table to advance the work tocutting position, a drive for said back gauge, an electric motoroperatively associated with said drive, and a limit switch mounted onsaid side gauge for adjustment lengthwise thereof adapted'to be actuatedby a reverse travel of the back gauge, whereby the rearward travel ofthe back gauge may be automatically terminated at any one of a pluralityof difierent points.

4. In a paper cutter, a table, a side gauge affixed to the table, a backgauge slidable over the surface of the table to advance the Work tocutting position, a drive for said back gauge, an electric motoroper'atively associated with said drive, a control for said motorcomprising means for inaugurating a rearward travel of the back gauge,and a limit switch mounted on said side gauge for adjustment lengthwisethereof adapted to be actuated by a rearward travel of the back gauge,whereby the rearward travel of the back gauge may be automaticallyterminated at any one of a plurality of difierent points.

5. In a paper cutter, a table, a back gauge slidable over the surface ofthe table to advance the work to cutting position, a drive for said backguage adapted to move the same rearwardly when a series of cuts havebeen completed, an electric motor operatively associated with saiddrive, a limit switch carried by a fixed part of the machine, saidswitch being adjustable to assume a plurality of different positionslengthwise of the direction of travel of the work and adapted to beactuated by the rearward movement of the back gauge, whereby therearward travel or the back gauge may be automatically terminated at anyone of a plurality of difierent points.

6. In a paper cutter, the combination of a table, a back gauge movablethereover, a drive for said back gauge, a hand wheel for operating saiddrive, an electric motor also operatively connected with said drive,means for conducting current to said motor, means for reversing thecurrent connections to the motor to effect a quick stop, and a zerospeed switch operatively associated with said motor for opening themotor circuit at the instant the motor shaft begins to turn in a reversedirection, whereby the hand wheel may be turned thereafter without dragother than the load imposed by the resistance to movement of the backgauge itself.

7. In a paper cutter, the combination of a table, a back gauge movablethereover, a drive for said back gauge, an electric motor operativelyconnected with said back gauge drive, a relay adapted to completeconnections for energizing said motor to effect rearward travel or" theback gauge, a hand switch for momentarily energizing said relay, aparallel circuit through said relay, a switch actuated by the rotationof the motor shaft for closing said parallel circuit, and means foropening said parallel ciricuit when said gauge reaches a predeterminedpoint in its rearward travel.

S. In a paper cutter, a reversible electric motor, a forward relay and areverse relay controlling the circuits to said motor to cause rotationthereof in the forward and reverse directions respectively, a switch inthe circuit of each relay arranged to be opened by the energization ofthe other relay, a zero speed switch operatively associated with theshaft of said motor arranged to make contacts in the circuit for theforward re-,

lay when the reverse relay is energized and to make contacts in thecircuit for the reverse relay when the forward relay is energized,whereby when the circuit for either relay is opened that for the otherrelay is automatically closed and

